STM32H747 DCMI DMA stops after one transfer - stm32

Question

I have a problem with STM32H747 Discovery board and OV5640 camera shield.
I configured DCMI interface and it works fine. I can see values in hdcmi->Instance->DR register changing and vsync and hsync interrupts work.
I want to transfer single line of pixels from DCMI to buffer in RAM. So I start DMA in circular mode with data length equal to line buffer size in words (32bit). Then I start DCMI in circular mode. Since then DMA should transfer each received line to buffer and then call transfer completed callback.
But there is a problem with DMA that transfers data. First line is transferred correctly, but then data in the buffer stays always the same. DMA transfer completed callback is called every line (checked with counting hsync and DMA TC interrupts).
This is how DMA is initialized in Cube:
cube dcmi dma init
Line buffer initialization:
uint8_t cameraLineBuffer[CAMERA_LINE_SIZE] __attribute__ ((aligned (32)));
Function starting DCMI with DMA:
HAL_StatusTypeDef DCMI_Start_DMA_line(DCMI_HandleTypeDef *hdcmi, uint32_t DCMI_Mode)
{
/* Process Locked */
__HAL_LOCK(hdcmi);
/* Lock the DCMI peripheral state */
hdcmi->State = HAL_DCMI_STATE_BUSY;
/* Enable DCMI by setting DCMIEN bit */
__HAL_DCMI_ENABLE(hdcmi);
/* Configure the DCMI Mode */
hdcmi->Instance->CR &= ~(DCMI_CR_CM);
hdcmi->Instance->CR |= (uint32_t)(DCMI_Mode);
/* Set DMA callbacks */
hdcmi->DMA_Handle->XferCpltCallback = DCMI_DMA_LineTransferCompletedCallback;
hdcmi->DMA_Handle->XferErrorCallback = DCMI_DMA_Error;
/* Enable the DMA Stream */
uint32_t pLineData = (uint32_t) cameraLineBuffer;
HAL_DMA_Start_IT(hdcmi->DMA_Handle, (uint32_t)&hdcmi->Instance->DR, pLineData, CAMERA_LINE_SIZE/4);
/* Enable Capture */
hdcmi->Instance->CR |= DCMI_CR_CAPTURE;
/* Release Lock */
__HAL_UNLOCK(hdcmi);
/* Return function status */
return HAL_OK;
}
What can cause such strange behavior? I looked at examples in FP-AI-VISION1 and AN5020 manual but I couldn't find anything that I missed.

Answer 1

Ok, so I finally figured out the problem. DMA just writes data to RAM memory. CPU tries to access it, but it was using cached memory. After first CPU access to buffer DMA stopped working, probably because data was transferred to cache and so was visible by CPU and in the debugger.
Final solution was to just disable D-Cache at all. This website explains the problem well.